 /*******************************************************************************
  * Copyright (c) 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.ui.internal;

 import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.expressions.EvaluationResult;
 import org.eclipse.core.expressions.Expression;
 import org.eclipse.core.expressions.ExpressionInfo;
 import org.eclipse.core.expressions.IEvaluationContext;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.ui.IEditorReference;
 import org.eclipse.ui.ISources;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.handlers.HandlerUtil;

 /**
  * Closes all editors except the one that is active.
  * <p>
  * Replacement for CloseOthersHandler
  * </p>
  *
  * @since 3.3
  *
  */
 public class CloseOthersHandler extends AbstractEvaluationHandler {
     private Expression enabledWhen;

     public CloseOthersHandler() {
         registerEnablement();
     }

     public Object execute(ExecutionEvent event) throws ExecutionException {
         IWorkbenchWindow window = HandlerUtil
                 .getActiveWorkbenchWindowChecked(event);
         IWorkbenchPage page = window.getActivePage();
         if (page != null) {
             IEditorReference[] refArray = page.getEditorReferences();
             if (refArray != null && refArray.length > 1) {
                 IEditorReference[] otherEditors = new IEditorReference[refArray.length - 1];
                 IEditorReference activeEditor = (IEditorReference) page
                         .getReference(page.getActiveEditor());
                 for (int i = 0; i < refArray.length; i++) {
                     if (refArray[i] != activeEditor)
                         continue;
                     System.arraycopy(refArray, 0, otherEditors, 0, i);
                     System.arraycopy(refArray, i + 1, otherEditors, i,
                             refArray.length - 1 - i);
                     break;
                 }
                 page.closeEditors(otherEditors, true);
             }
         }

         return null;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.internal.AbstractEvaluationHandler#getEnabledWhenExpression()
      */
     protected Expression getEnabledWhenExpression() {
         if (enabledWhen == null) {
             enabledWhen = new Expression() {
                 public EvaluationResult evaluate(IEvaluationContext context)
                         throws CoreException {
                     IWorkbenchWindow window = InternalHandlerUtil
                             .getActiveWorkbenchWindow(context);
                     if (window != null) {
                         IWorkbenchPage page = window.getActivePage();
                         if (page != null) {
                             IEditorReference[] refArray = page
                                     .getEditorReferences();
                             if (refArray != null && refArray.length > 1) {
                                 return EvaluationResult.TRUE;

                             }
                         }
                     }
                     return EvaluationResult.FALSE;
                 }

                 /*
                  * (non-Javadoc)
                  *
                  * @see org.eclipse.core.expressions.Expression#collectExpressionInfo(org.eclipse.core.expressions.ExpressionInfo)
                  */
                 public void collectExpressionInfo(ExpressionInfo info) {
                     info
                             .addVariableNameAccess(ISources.ACTIVE_WORKBENCH_WINDOW_NAME);
                 }
             };
         }
         return enabledWhen;
     }
 }

